A touch panel is an electronic part which is constructed of a matrix-shaped touch sensor laminated on an LCD (liquid crystal display) panel, for example, and is a display input device that can allow a user to touch an input button display area, such as an icon displayed on the LCD panel, by using an object to be detected, such as a finger or a pen, and detect information about the coordinate position of a part on the screen which has been touched by the user to enable the user to operate target equipment. Therefore, in many cases, a touch panel is used while being incorporated into equipment, such a vehicle-mounted navigation system or a bank ATM (Automatic Teller Machine), which has to meet the need for the user to handle the equipment by following a self-explanatory procedure.
Many proposals for improving the operability and user-friendliness of a touch panel as mentioned above have been applied for patent.
For example, a display input device which, when a user brings his or her finger close to the device, enlarges and displays a key switch which is positioned in the vicinity of the finger so as to facilitate the user's selection operation (for example, refer to patent reference 1), a CRT device which detects a vertical distance of a finger and displays information with a scale of enlargement according to the distance (for example, refer to patent reference 2), an input unit equipped with a touch panel which detects whether or not a user's hand is in contact with an arm switch and changes an arrangement of icons when detecting that the user's hand is in contact with the arm switch (for example, refer to patent reference 3), and so on have been known.